 
 (defn- group-free*
   "Free synth groups, releasing their resources."
-  [& group-ids]
-  (ensure-connected!)
-  (apply node-free group-ids))
+  [group-id]
+  (ensure-connected!)
+  (node-free group-id))
 
 (defn node-pause*
   "Pause a running synth node."

   :node-block-until-ready node-block-until-ready*})

(extend SynthGroup
  IControllableNode
  {:node-control           node-control*
   :node-control-range     node-control-range*

   :group-clear        group-clear*
   :group-deep-clear   group-deep-clear*
   :group-post-tree    group-post-tree*
   :group-node-tree    group-node-tree*
   :group-free         group-free*}

  IKillable
  {:kill* group-deep-clear*})
